Most cultures that cremate their dead won't throw the ashes into the Ganges (not even most Hindus, historically - the vast majority of Indians don't live within

Most cultures that cremate their dead won't throw the ashes into the Ganges (not even most Hindus, historically - the vast majority of Indians don't live within walking distance from the Ganges), but bury them in urns, which are often very recognizable in the archeologic record.